Gayle buys 8 biros for £3.
three of them are black.
the others are red.
each red biro costs 45p.
hat is the cost of one black biro?

Which function can be used to model the monthly profit for x trinkets produced? f(x) = –4(x – 50)(x – 250) f(x) = (x – 50)(x – 250) f(x) = 28(x + 50)(x + 250) f(x) = (x + 50)(x + 250)